1. Field of the Invention
The present invention relates to an image forming apparatus such as a printer for performing print onto a recording medium such as a recording sheet or a film for over head projector (OHP sheet) and, more particularly, to a control of a conveying operation of the recording medium, namely, a paper feeding control.
2. Related Background Art
In a conventional printer, a command is sent to a mechanism control unit in accordance with analysis by a print data analyzing unit, thereby first performing a paper feeding operation. After the paper feeding operation is confirmed, a printing operation is performed by alternately sending a print command and a paper feed command to the mechanism control unit. After the printing operation, a paper ejection command is executed to perform a paper ejecting operation. When the print of the next page is successively executed after the print of one page, the printer waits for the end of the paper ejecting operation and, after that, executes the paper feeding operation for the next page.
In the above paper feeding control, however, since the printer certainly waits for the end of the paper ejecting operation and then performs the paper feeding operation for the next page, when data of a large amount of pages is printed, most of the print operating time is used for time of the paper feeding and ejecting operations, so that there is a problem that the throughput is remarkably deteriorated.
In Japanese Patent Application Laid-Open No. 8-73062, as a technique for improving the throughput of a paper conveying operation, a construction in which the rear end of a sheet is detected by a sensor and a paper feeding of the next sheet is controlled on the basis of the detection result has been disclosed. Specifically speaking, there has been disclosed a construction in which, on the basis of the result obtained by detecting the rear end of the sheet, the printed sheet is conveyed to a position where the next sheet can be fed, the next sheet is fed in this state, and simultaneously, a paper ejecting operation of the previously printed sheet is performed. However, in the construction disclosed in the prior art, it is necessary to detect the rear end of the printed sheet.
The present invention is made in consideration of the problems. According to the present invention, it is an object to provide an image forming apparatus that is capable of improving the throughput of a continuous printing operation by reducing time needed for paper feeding and ejecting operations, its controlling method, and a storage medium.
In order to accomplish the above object, according to the present invention, there is provided an image forming apparatus comprising: deciding means for deciding whether or not print is continuously performed to the other sheet subsequent to a sheet that is being printed; and controlling means for starting a paper feeding operation of the subsequent sheet during a paper ejecting operation after the print to the sheet which is being printed in the case where it is decided by the deciding means that the print is continuously performed.
According to the image forming apparatus of the present invention, when it is decided by the deciding means that the print is continuously performed, ejecting the sheet is stopped at a desired position in the paper ejecting operation of the sheet which is being printed and, subsequently, the paper ejecting operation is started again and the paper feeding operation of the subsequent sheet is also started.
According to the present invention, there is provided an image forming apparatus for printing while scanning a print head in a main scanning direction, comprising: paper feeding means; position managing means for managing a paper feeding position; storing means for storing the length of a print sheet; detecting means for detecting whether data exists on the next page or not; and controlling means, wherein when it is detected by the detecting means that data exists on the next page, the controlling means decides a position where the sheet for the next page can be fed due to the position managing means and the length of the print sheet stored in the storing means, the paper ejecting operation due to the paper feeding means is temporarily interrupted at the position, and the residual paper ejecting operation is performed simultaneously with the paper feeding operation for the next page.
According to the present invention, there is provided a controlling method of an image forming apparatus comprising: a step of deciding whether or not print for the other sheet is continuously performed subsequent to a sheet that is being printed; and a step of starting a paper feeding operation for the subsequent sheet during a paper ejecting operation after the print of the sheet which is being printed when it is decided in the step that the print is continuously performed.
The invention includes a storage medium in which a program for realizing the controlling method has been stored.